Drop-on-demand inkjet printers are commonly categorized according to one of two mechanisms of drop formation within an inkjet printhead. Thermal bubble inkjet printers use thermal inkjet printheads with heating element actuators that vaporize ink (or other fluid) inside ink-filled chambers to create bubbles that force ink droplets out of the printhead nozzles. Piezoelectric inkjet printers use piezoelectric inkjet printheads with piezoelectric material actuators that generate pressure pulses inside ink-filled chambers to force droplets of ink (or other fluid) out of the printhead nozzles.
Piezoelectric inkjet printheads are favored over thermal inkjet printheads when using jetable fluids whose higher viscosity and/or chemical composition prohibit the use of thermal inkjet printheads, such as UV curable printing inks. Thermal inkjet printheads are limited to jetable fluids whose formulations can withstand boiling temperature without experiencing mechanical or chemical degradation. Because piezo printheads use pressure (not heat) to force ink droplets out of nozzles, piezo printheads can accommodate a wider selection of jetable materials. Accordingly, piezo printheads are utilized widely to print on a variety of media substrates.
However, one problem associated with piezoelectric printheads is the construction of the MEMS (microelectromechanical systems) and piezo-actuator drive circuitry in a manner that minimizes the printing system cost. There are certain features of piezoelectric printheads that require electronic circuit control on a per-nozzle basis. For example, trimming individual nozzles and reducing crosstalk between adjacent nozzles requires the use of separate electronic circuitry for each nozzle. However, implementing the per-nozzle electronic circuitry requires additional area in the printhead which increases the printhead cost. Thus, constructing piezoelectric printheads that have a high nozzle density and a low cost is an ongoing challenge.